1. Field of the Invention
This invention generally relates to a cable operated disc brake for a bicycle. More specifically, the present invention relates to a cable operated disc brake with a disc brake pad adjustment mechanism to adjust the spacing between the friction pads.
2. Background Information
Bicycling is becoming an increasingly popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving their components. One particular component of the bicycle, which has been extensively redesigned over the past years, is the braking systems of bicycles. In particular, the braking power of the braking systems is constantly being increased.
There are several types of bicycle brake devices, which are currently available on the market. Examples of some types of common bicycle brake devices include rim brakes, caliper brakes and disc brakes. If a rider wants a very high performance brake system, then the rider typically wants a disc brake system. Disc brake systems provide a substantial braking power in relationship to the amount of braking force applied to the brake lever. Moreover, disc brake systems typically provide a high level of consistency in all types of weather and riding conditions. Of course, riders constantly desire better performance from disc braking systems, i.e., disc brake systems that have more braking power.
Conventionally, a disc brake is composed of a pair of brake pads that are movably mounted to a caliper housing. The brake pads are pressed against a disc or rotor that is fixed to the wheel to halt the rotation of the disc and thus the wheel. The brake pads are moved toward the disc hydraulically or mechanically such as by a cam mechanism. The hydraulic disc brake systems are typically complicated in construction and expensive to manufacture. Moreover, hydraulic disc brake systems are often quite heavy in construction.
The mechanical disc brake system includes a caliper housing with one brake pad that is fixed to the caliper housing and one brake pad that is movably mounted to the caliper housing by a cam mechanism. A swinging arm is coupled to the cam mechanism to move the movable pad by a cam action. Typically, a conventional brake cable is coupled to a brake lever to move the swinging arm, and thus, operate the cam mechanism. While mechanical disc brake systems are typically less expensive and lighter than hydraulic disc brake systems, mechanical disc brake systems can still be complicated in construction and requires many parts resulting in expensive manufacturing costs, as with a hydraulic disc brake system.
In both hydraulic and mechanical disc brake systems, the brake pads need to be spaced apart by a predetermine distance to receive the rotor between the brake pads. The brake pads should be slightly spaced from the rotor when the brake system is in the non-braking position. It is desirable to control the spacing between the brake pads and the rotor to ensure good braking. Thus, when the brake pads and/or the rotor becomes worn, the spacing between the brake pads and the rotor becomes larger. Thus, the brake pads must be moved farther to engage and stop the rotor.
In view of the above, there exists a need for a disc brake pad adjustment mechanism to adjust the spacing between the friction pads. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
One object of the present invention is to provide a disc brake that has a disc brake pad adjustment mechanism to adjust the spacing between the friction pads.
Another object of the present invention is to provide a cable disc brake that is relatively compact and lightweight in relation to the amount of braking power.
Another object of the present invention is to provide a cable disc brake that is relatively inexpensive to manufacture.
The foregoing objects can be basically attained by providing a disc brake pad adjustment mechanism that controls the spacing between a pair of friction pads. The disc brake pad adjustment mechanism has a caliper housing portion, an adjusting axle, an adjusting plate and an adjustment biasing member. The adjusting axle movably is coupled to the caliper housing portion to rotate about a longitudinal axis of the adjusting axle. The adjusting plate is coupled to the adjusting axle to move axially along the longitudinal axis of the adjusting axle upon rotation of the adjusting axle relative to the caliper housing portion. The adjustment biasing member is operatively disposed between the caliper housing portion and the adjusting axle and arranged to axially urge the adjusting axle against the caliper housing portion. The adjusting axle and the caliper housing portion is configured with an indexing arrangement therebetween to selectively retain the adjusting axle in a predetermined angular position about along the longitudinal axis of the adjusting axle relative to the caliper housing portion.
The foregoing objects can also be basically attained by providing a cable disc brake comprising a caliper housing, a first friction pad, a second friction pad, an actuated mechanism, a friction pad biasing member and a disc brake pad adjustment mechanism that controls the spacing between a pair of friction pads. The first friction pad is movably coupled to the caliper housing between a release position and a braking position. The second friction pad is coupled to the caliper housing and arranged substantially parallel to the first end friction member to form a rotor receiving slot therein between. The cable actuated mechanism is movably coupled to the caliper housing to move the first friction pad from the release position towards the second friction pad to the braking position. The disc brake pad adjustment mechanism has an adjusting axle, an adjusting plate and an adjustment biasing member. The adjusting axle movably is coupled to the caliper housing to rotate about a longitudinal axis of the adjusting axle. The adjusting plate is coupled to the adjusting axle to move axially along the longitudinal axis of the adjusting axle upon rotation of the adjusting axle relative to the caliper housing. The adjustment biasing member is operatively disposed between the caliper housing and the adjusting axle and arranged to axially urge the adjusting axle against the caliper housing. The adjusting axle and the caliper housing is configured with an indexing arrangement therebetween to selectively retain the adjusting axle in a predetermined angular position about along the longitudinal axis of the adjusting axle relative to the caliper housing.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.